In our Database Management class, our next project deliverable is to
normalize our database to 3NF. The argument has come up that in our database,
any entity that has City, Zipcode and State has a transitive dependency
between the three. One of our team mates says to resolve this issue we should
put all three attributes into one table with CityID (An autonumber) as the
foreign key to any other tables. His reasoning that if you know the City, you
then know the Zip code and State does not work because some of the Cities
have multiple Zip codes.

This would be the relationship schema he wants to use.

tblVendor (VendorCode, Season, BusName, RepName, Address, CityID,
PhoneNumber, AltPhoneNumber, Email)

One issue is that in our database, which is used by a local business who
only deals with people and business in about a 50 mile radius, is that since
there are a limited number of Cities, Zip codes and for the most part the
default value for state is NY, that they are in separate tables for City, Zip
code and State and these are basically used to fill combo boxes on a form for
data entry.

This would be the relationship schema I want to use.

tblVendor (VendorCode, Season, BusName, RepName, Address, CityID, ZipcodeID,
StateID, PhoneNumber, AltPhoneNumber, Email)

The real issue is that we only have to worry if they are transitive
dependencies, the Professor told us to work this out by researching the idea,
and one way to research this would be to ask the experts for their advice. So
any input to us would be greatly appreciated.

Thanks
CoachBarkerOJPW